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GaussStrife
  • Member for 3 years, 8 months
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4 votes
Accepted

Partial Trace of Werner State

4 votes
Accepted

How to derive $|0\rangle=\frac{1}{\sqrt{2}}(|+\rangle+|-\rangle)$?

3 votes
Accepted

Why is a conjugate transpose of $|+\rangle$ a vector $1/\sqrt{2} (\langle0| + \langle1|)$?

3 votes
Accepted

If $\rho,\sigma$ are classical-quantum states, can the fidelity $F(\rho,\sigma)$ be expressed in terms of $F(\rho_i,\sigma_i)$?

2 votes
Accepted

How do I show that $R_z(\theta)=e^{-iZ\theta/2}$?

2 votes
Accepted

Why is the quantum discord of $\rho$ zero iff $\rho=\sum_j p_j \pi_j\otimes \rho_j$ for mutually orthogonal projections $\pi_j$?

2 votes

How do you CNOT between qubits faraway from each other?

2 votes

Derivation of the identity $\sum_j p_j \langle \psi_j|M|\psi_j \rangle = \sum_j p_j \operatorname{tr}\left(|\psi_j \rangle \langle \psi_j|M\right)$

2 votes

What does $I$ represent in the expression $A\otimes I$?

2 votes

Is a "Bell measurement" equivalent to a projective measurement in a different basis?

1 vote

In the solution of exercise 2.2(on this site) how can we see the new form of the operator A, in the beginning of the answer.?

1 vote
Accepted

Matrix representation of multi-qubit operations when there's irrelevant qubit(s)

1 vote

Why should we purify a mixed state?

1 vote

How is outer product an operator?

1 vote
Accepted

Quantum discord of a tripartite system A:BC

1 vote

Reduced density matrix of the ensemble of two-qubit state that is possessed by Alice and Bob

1 vote

Post-selection applied to quantum teleportation

1 vote

What does the unitary $[|0\rangle\langle 0|\otimes I+|1\rangle\langle1|\otimes(|1\rangle\langle 0|+|0\rangle\langle1|)]\otimes I$ represent?

1 vote
Accepted

Concavity of Conditional Quantum Entropy

1 vote

What it means that the quantum teleportation involves projection onto a maximally entangled state?

1 vote

What is a maximal entangled multipartite state?

1 vote

Measure a state in Hadamard basis

1 vote

How is the additivity of accessible information, $\frac{1}{n} I_{\rm acc}(\rho^{\otimes n})=I_{\rm acc}(\rho)$, proved?

1 vote

How do we change the basis of a given qubit state?

1 vote

How to prove the positivity of the conditional quantum mutual information, $I(A;B|C)\ge0$?

0 votes

Is the square root of SWAP gate "maximally entangling"?

0 votes

Can we write the density operator as a sum of mixed states?

0 votes

How does a unitary transformation preserve a measurement?